function plot_alp_s(D)
%太阳高度角变化曲线


t=0:0.5:24;
for i=1:length(t)
    alpha_s(i)=alp_s(D,t(i));
end
plot(t,alpha_s);

xlim([0 24]);
xlabel('时刻');
ylabel('太阳高度角(℃)');

title('太阳高度角变化曲线图');

xticks(0:4:24);

need_t=[9 10.5 12 13.5 15];%题目所求特定时间的太阳高度角位置
for i=1:length(need_t)
    need_alpha_s(i)=alp_s(D,need_t(i));
end

hold on;
plot(need_t,need_alpha_s,'*');

end

